Quoth Dan Youngquist.....
There is neither allow-hotplug nor iface on the live CD.
Is there a NIC detected?
Try ifconfig. If it shows eth0 then....
ifconfig eth0 192.168.1.100 route add default gw 192.168.1.200
edit /etc/resolv.conf to add a nameserver; insert a line
nameserver 192.168.1.200
(obviously replacing 192.168.... with your IP addresses in all the above).
That should get your networking up.
If there's no eth0 shown in the first ifconfig then you'll need to load the NIC driver. Shout if that's the case and further suggestions will be forthcoming.